S-4: Difference between revisions

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==Internals==
==Internals==
The S-4 sampling gate is based upon a traveling wave trapped-charge transmission line in which the sampling window is set by the propagation time of a pulse edge through a thick-film transmission line. This technique requires only a sharp pulse edge rather than a precise pulse width, which is harder to generate.
The S-4 sampling gate is based upon a traveling wave trapped-charge transmission line  
in which the sampling window is set by the propagation time of a pulse edge through a thick-film transmission line.  
This technique requires only a sharp pulse edge rather than a precise pulse width, which is harder to generate.
The sampling diodes are housed in a special coaxial connector that provides a high bandwidth signal path.
The sampling diodes are housed in a special coaxial connector that provides a high bandwidth signal path.


To disassemble the sampler hybrid, first remove it from the sampler board as per the manual. Remove the input
To disassemble the sampler hybrid, first remove it from the sampler board as per the manual.
connector using a 7/32" wrench and remove the 20 dB attenuator with small plyers. The ceramic board is held
Remove the input connector using a 7/32" wrench and remove the 20 dB attenuator with small pliers.
to the housing using roll pins that can be pressed out with a 0.030" pin punch. The hybrid has six diodes,
The ceramic board is held to the housing using roll pins that can be pressed out with a 0.030" pin punch.
each about 0.75mm square. The cathodes are glued to the gold substrate with conductive epoxy and the anodes
The hybrid has six diodes, each about 0.75mm square.
are wire-bonded (twice) over a gap to the next step in the strobe line. It appears that a standard beam-lead
The cathodes are glued to the gold substrate with conductive epoxy and the anodes
diode may fit across the gap but cleanly removing a failed diode without damaging the substrate would be
are wire-bonded (twice) over a gap to the next step in the strobe line.
quite difficult.
It appears that a standard beam-lead diode may fit across the gap
but cleanly removing a failed diode without damaging the substrate would be quite difficult.


==Links==
==Links==

Revision as of 09:06, 27 December 2017

Template:Plugin Sidebar 2 The Tektronix S-4 is a sampling head for 7000- and 3S-series samplers. It was designed by George Frye and introduced in 1968. It is the fastest of the S-series plug-in samplers.

Key Specifications

Rise time 25 ps (observed with S-50 or S-52, 35 ps)
Bandwidth 14.5 GHz
Input impedance 50 Ω (terminated SMA connector)
Input range operating, 1 Vp-p; max. safe overload, ±5 V
Noise < 5 mV
Features
  • trigger signal pick-off for internal triggering

Internals

The S-4 sampling gate is based upon a traveling wave trapped-charge transmission line in which the sampling window is set by the propagation time of a pulse edge through a thick-film transmission line. This technique requires only a sharp pulse edge rather than a precise pulse width, which is harder to generate. The sampling diodes are housed in a special coaxial connector that provides a high bandwidth signal path.

To disassemble the sampler hybrid, first remove it from the sampler board as per the manual. Remove the input connector using a 7/32" wrench and remove the 20 dB attenuator with small pliers. The ceramic board is held to the housing using roll pins that can be pressed out with a 0.030" pin punch. The hybrid has six diodes, each about 0.75mm square. The cathodes are glued to the gold substrate with conductive epoxy and the anodes are wire-bonded (twice) over a gap to the next step in the strobe line. It appears that a standard beam-lead diode may fit across the gap but cleanly removing a failed diode without damaging the substrate would be quite difficult.

Links


Pictures